随着汽车的高速化,高强度螺栓的使用量有增加的倾向。自1973年末石油冲击以来,各公司对“省能”关心了,均在努力降低车辆自重和油耗。汽车螺栓则有小形化和高强度化的倾向。福特汽车公司成功地把六角头螺栓的头部形状进行了改小(图1),大幅度地节约了材料,降低了成本。下面以要求最严格的发动机用高强度螺栓为中心,将其特点、制法和热 As automobiles have increased in speed, the use of high-strength bolts tends to increase. Since the oil shock in late 1973, companies have been concerned about “saving energy” and are trying to reduce the weight and fuel consumption of vehicles. Automotive bolts tend to be smaller and stronger. Ford Motor Company successfully changed the head shape of the hexagon head bolt (Figure 1), saving material and reducing costs. Below to the most stringent requirements of the engine with high strength bolts as the center, its characteristics, methods and heat